And another thing is that this does not happen in this shower all the time, its intermittent. After draining the tank, run the hot water for a few minutes to determine if the unusual smell and colors are gone. Another problem that tankless water heaters can run into is that of a cold water sandwich— a plumbing term given to sudden temperature fluctuations, when your tankless water heater produces hot and cold water intermittently. You get a very slow gradual drop in temperature, but it doesn't drop suddenly after a few minutes like the pex solution would. We just started having the same issue...hot for 5 min or so and then cold. A dirty water filter on the cold water inlet. Cold water sandwich or hot water temperature fluctuates. Well, if your hot water is suddenly turning lukewarm/cold after a few minutes, you most likely have a problem with your hot water heater. No one else is in the house using hot water, so that's not it. Oct 4, 2018 - If your hot water turns cold after a few minutes you most likely have a defective dip tube. Shut off the cold water to the heater. A water softener will not only resolve this problem, but can improve your quality of life too, by making your showers and baths more refreshing, helping your drinking water taste better, and even helping your laundry last longer. Tankless water heaters are a great investment for your home or office. Turn the knob to cold a bit, again, it drops a few degrees, then slowly goes right back up. When the shower is running cold, the sinks upstairs are still running hot. This unit is equipped with an internal freeze protection … Simply click here to return to Troubleshooting. First, you can turn the thermostat down on the water heater. Switching from a tank-style water heater to a tankless water heater will save a family of four an average of $100 per year or over $1500 throughout the lifetime of the system, according to Energy Star. But the sinks will be hot when the shower is cold??? If you had a glass of hot water and you had cold water in your mouth, with a straw you use as the diptube sending the cold water to the bottom of the glass"the water heater", you would have more hot water above the cold water. Our water heater is 7 years old. If I turn off the shower or just wait with the cold water running, about 5 minutes later it is hot again. So I replaced the low-flow shower head with a normal shower head and the problem has not occurred again. Finally, another issue that homeowners often find with their tankless systems—if not properly installed and maintained—is mineral buildup. In most cases, a tankless on-demand water heater fails to supply enough hot water if the unit is too small. After a few minutes of running, the boiler turns off, and water temperature gradually declines for a few minutes, until the boiler turns back on, and water temperature jumps back up again. However, when the tap is turned off, so too is the hot water supply. More Can Go Wrong Than Right. As stated above, you will have installed 2 tank style heaters in the same amount of time you install 1 tankless. What To Do If Your Hot Water Turns Cold After A Few Minutes. Water stays cold. #3. … Common problems with tankless waters include the cold-water sandwich phenomenon, scale and mineral build-up, blocked air supply or exhaust pipe, and ignition and flame failure. He's checked the pump and it's running ok. You can see where the dip tube is located in this diagram. Why Is My Tankless Water Heater Running Hot and Cold? A tepid or cold stream of water may be an indication that your water heater is not set to the right temperature. of the straw in the water you would have less hot water above the cold water. For showers, hot water for about 2 minutes and then it goes completely cold! For most tankless water heaters, the display with present … While many backup battery systems may be compatible with tankless water heaters, the HUGO Battery Backup for Tankless Water Heaters (available on Amazon) is the only model specifically designed for use with tankless water heaters.Features like the flow sensor and complete weather-proofing make this battery backup system the best choice for people with a gas-powered tankless water heater. If neither of these factors are properly addressed, then the tankless water heater might not be able to meet the demand being placed on it and will fail to work, as its computer system will be overloaded. (los angeles, ca). sites. So your water heater used to provide an adequate amount of hot water to keep you content. The simplest way to identify a return of water in your house is by going to the Titan Tankless Water Heater. Water heater repair is a delicate task. the super tech I talked to believes its the blower. Just clean it and it should fix the problem. The dip tube is in the water heater tank and shoots cold water to the bottom of the tank where the heating of the water occurs. We’re talking about the accumulation of calcium and magnesium. Ask Your Own HVAC Question. it took a couple minutes, but went away. Rigby, Banging or rumbling noises. What is hard water? Here are a few examples of other things that might cause a tankless water heater to unexpectedly turn off: using a water-saving shower head and the temperature on water heater is set too high; a dirty cold water inlet filter; flow-sensor damage or problem Concept is to use an electric tankless heater to pre-heat water going into my gas tank-type water heater. The cold water will eventually turn to hot after a few minutes. Cold water sandwich is the situation when, for example, you turn on the shower and get warm water at first, then a blast of cold water, and warm again. Doesn't go completely cold but not even luke warm after a few minutes. Hot water runs out in the shower and faucet. Soon after, the boiler turns on, and water remains hot. Advanced Home Services is the standard when it comes to providing great service. Unusual odors. When the water is turned on, cold water travels over the coils, becoming hot. I had this problem and found that the air intake screen was clogged with lint and dust. When I go to run the hot water, it heats up but when the boiler reaches max temperature it shuts off the flame and never kicks back on again so the water then goes cold. If mineral buildup has already occurred in your tankless water heater’s lines, then you will need a professional to clean these lines before continuing to use your water heater system. At a rate of approximately 1.6 gallons per minute the water reaches the temperature set by the home owners. OK lets go over a few Tankless water heater basics. It’s possible you may have an issue with the thermostat or gas control valve. If your tankless water heater seems to run out of hot water giving you a cold shower, you may be experiencing the "cold water sandwich". Not only are they highly efficient, but they can also save you money by heating water only on-demand. Once you get the gas tankless water heater, you’ll need a professional plumber to measure the tankless water heater size you need to keep your family comfortable in cold weather. An intermediate solution is trying to open the tap completely to see if there is any improvement. And for years it had worked correctly. you have hot water on demand), there is no cause for concern. Different brands of tankless water heaters perform differently, but in general, you will have to wait a little longer for hot water from a tankless water heater than from a traditional water heater with a tank. Very frustrating! Hard water is water that has a higher dissolved mineral content. Why does my tankless water heater go cold? Today’s gas water heaters have air inlet screens at the bottom of the water heater that can get clogged with dust, dirt, soot, cat hair, lint, etc. When you turn out other faucets at the same time, that increases water flow out of the water heater and keeps the heater turned on. What to do: Have a … If not, you should also check the error code displayed on the heater, and look it up to see what is happening with your Navien heater. Your tankless water heater will feel cold to the touch when the heater unit and pumps are in the rest state and not heating water. These valves automatically change Unlike traditional hot water heaters using a storage tank, the tankless units have no storage tanks and thereby have no standby heat loss—the heat lost and energy wasted by heating water only to store it in a tank, a character flaw of traditional hot water heaters. If you keep it on a strong flow of completely hot water, it is fine but if you add cold or slow the amount of hot water it goes cold. Tank water heaters store a large amount of hot water, and when it’s not used promptly, the air surrounding the tank can cause it to cool off, wasting your energy. A plumbing system crossover where there shouldn’t be one. Follow. An improperly sized gas line, as mentioned above. A hot shower in the morning is the best way to start the day – and a warm shower or bath at the end of the day is perfect for resting and relaxing.. A tank is a thermal expansion reservoir. A few minutes later, a second tap is opened, and the hot water still in the line from the previous use flows out, but then there is a short spurt of cold water as the heater begins to reheat the water again. Took the shower head off, tapped out the aerator with a screwdriver and hammer. Map & Directions [+], Serving Homes & Business Throughout Southeast Idaho, Heating and Cooling Contractor License # HVC-C-5806, Registered Entity Contractor License # RCE-3731, Pocatello, ID tankless water heater installation. Join in and write your own page! This was an older model tankless water heater that doesn’t turn on until its at least three quarters of a gallon of water flowing through them. It will only take you a few minutes to install the gas water heater according to the instructions. I have a Noritz tankless water heater. Simply click here to return to. The cold-water sandwich phenomenon. The problem is that I run out of hot water in the winter time when everyone is showering in the morning. Those valves are to prevent hot water from entering the cold water supply line, and cold water from entering the recirc hot water return line. Then it returns to normal hot water and stays that way until I'm done. Since tankless water heaters don’t maintain a supply of hot water, it takes time for the cold water to flush out of the pipes and the heated water to reach your faucet. Category: Plumbing. (assuming the water at the bottom of the water heater is cold and the thermostat is turned up to 120 degrees f ) To replace the thermostat MAKE SURE TO TURN THE POWER OFF. reservedhome-water-heater.com is a participant in the Amazon I commented before as anonymous, re: only 1 shower turning cold in middle. $1482.00 to install a 50 gallon power vent water heater and about $2800.00 for a 199k btu tankless water heater. Called Rheem to troubleshoot and they said to replace the flame rods. What you don’t know is that issues in your tankless unit develop over time, and may eventually have an impact on water quality, water pressure and the overall volume of water available to your home. Ask Your Own Plumbing Question. Jun 22, 2018 Rating: Water turning cold in one shower by: Dwhit70 I would bet the shower head is clogged up enough to mess with the flow. Tankless. (Michigan) I figure I can use a low power electric unit just to bring the water up to 75 or 80F and let the gas heater do the rest. If it takes more than a minute, you should contact the installer to see if there’s an opportunity to adjust the settings so that you can access hot water more quickly. provide a means for us to earn fees by linking to Amazon.com and affiliated They can be placed near any hot water-requiring fixtures like washing machines with a power supply. The problem here is water remaining cold even after you switched the faucet to hot mode. A few years ago we installed a tankless hot water heater and we love it. Appreciate any thoughts on what the problem may be and how to resolve it. If it’s broken, cold water fills the top of the heater and begins to flow right out the hot side. Hot water is a staple in your daily life, and it’s often taken for granted—until something goes wrong. More specifically, you probably have a bad dip tube. The guidelines for most tank heaters recommend a water temperature of 120 degrees. This is a very unpleasant situation for the users, especially when taking a shower. If you consider how one works (dip tube sends cold water to bottom of tank, the flame heats it up, and hot water exists from the top of the tank) this obviously shouldn’t be happening (warm water changes to hot after a few minutes). This requires a fair amount of plumbing skills and knowledge, so many homeowners will need help from a professional to complete the replacement project. Services LLC Associates Program, an affiliate advertising program designed to Then the water heats from cold every time the water is turned on so the heater can not get hot enough to heat cold water for a few seconds and cold water will follow the hot water in the pipes. Thanks! 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